Specifications
JASCO's J-810 Circular Dichroism Spectropolarimeter a comprehensive Chiro-optical Spectrometer, it is a the latest acquisiton for the BRIN Laboratory (W186). It is a Circular Dichroism and UV/Visible absorbance research-grade chiroptical spectrometer.
The J-810 offers hardware and software features to save time and deliver even better results. Instrument control and data processing are handled by user-friendly Spectra Manager for Windows PC platform. Increased Performance of the J-810's optical bench, with dual prism optics, and the 150-watt air cooled lamp housing provide remarkable stability and low maintenance cost.
The J-810 optical performance gives:
Baseline stability Noise and drift Precision and Accuracy
Features
Light source: 150 W Xenon arc lamp (air cooled) Sample chamber: small or large - designed for various experimental techniques Wavelength range: 163 ~ 900 nm (standard)
Four Channel Simultaneous Data Acquisition: Input channels: 2 internal plus 2 external signals can be acquired simultaneously Spectra Manager Software - Instrument software is now Spectra Manager system running on Windows 2000 and will update of XP version. Alarms Autoscale during measurement Validation systems (and software) for GLP/GMP and regulatory compliance
Data
Spectra Manager software to make data acquisition and analysis simple and reliable.
Compatible with Windows 2000 the software is reliable and will be upgraded to Windows XP The GUI allows overlay and subtractraction of spectra using drag and drop Data can be converted using a variety of algorithms Secondary structure can be analyzed by our own or any of the data packages available, even over the internet (see the Dichroweb service) Macro Manager allows simple and sophisticated experimental design
Other features
Easier operation through greater PC control of instrument facilities such as o Shutter o N2 purge gas control o PMT HT setting during manual measurements and light source power on/off o Compact design o Built-in light source power supply o Sample chamber liquid leakage sensor
What is CD?
Circular Dichroism (CD) is observed when optically active matter absorbs left and right handed circularly polarized light slightly differently. It is measured with a CD spectropolarimeter, which is able to measure accurately in the far UV at wavelengths down to 190-170 nm. In addition, the difference in the left and right handed absorbance is very small (usually in the range of 0.0001 absorbance units) corresponding to an ellipticity of a few 1/100th of a degree. The CD spectrum is the wavelength dependency of the difference in absorption between the right and left-handed components.
The units of CD
The units used in CD spectroscopy often cause confusion! The J-810 gives its raw output in ellipticity, and is measured in millidegrees (mdeg).
Circular Dichroism (CD) Spectroscopy
Circular Dichroism (CD) is observed when optically active matter absorbs left and right hand circular polarized light slightly differently. It is measured with a CD spectropolarimeter, which is relatively expensive. The instrument needs to be able to measure accurately in the far UV at wavelengths down to 190-170 nm. In addition, the difference in left and right handed absorbance A(l)- A(r) is very small (usually in the range of 0.0001) corresponding to an ellipticity of a few 1/100th of a degree. The CD is a function of wavelength. CD spectra for distinct types of secondary structure present in peptides, proteins and nucleic acids are different. The analysis of CD spectra can therefore yield valuable information about secondary structure of biological macromolecules.
